Petroleum or gasoline is rather flammable, and any negligence in handling it represents a fire hazard. Today, it is the tendency to operate a gas station automatically and by computer, and any possible problem concerning a safe operation must be considered because of the operator being not quite familiar with the dispenser. Particularly, after a given quantity of fuel has been filled into a tank, the flowing fuel has to be shut off definitely.
In view of the aforesaid facts, the inventor has, through repeated studies, developed a device in a dispenser that can automatically shut off the flowing fuel and can also sense the fuel level in a tank being filled. The device provides greater safety and higher convenience during operation.